Flange reinforced embossment



Sept 12, 1961 A. G. scHlLBERG 2,999,312

FLANGE REINFORCED EMBOSSMENT Filed DeG- 29, 1955 Fig. 1

Fign

IN VEN TOR. ARNOLD S C11/Luang Filed Dec. 29,1955, Ser. No. 556,130

,1 Claim- (Cl. 279-7545) .This invention relates to a ange reinforcedbearing structure `or embossment 'whichv may be vemployed in aVehic'lecontrol arm 'or other machine'element and the method of makingthe'same.

Vehicle 'control arm elements and other 'machine elements are commonlyprovided with an extruded tubular enibossment 'adjacent one 'or both'ends Ythereof for 'receiviug a 'shaft or the like.' The embossment'isgenerally `reinforced' by a yconcentric ange formed coextensively'withthe embossment and spacedradia'lly therefrom.

' Heretofore, the embossment and concentric iiange 'have been formed bya single stroke in a press 'with the bending operation'forformng vthellange being v'completed before' the 'extrusion is begun'. This methodrequires that aconsiderable 'radial clearance be provided'between theange 'and the'outer'wall of the embossment'so that adequate metal isavailableifor a successful' extrusion. In vthe 'case of achannel-section vehicle controlarm element provided 'with 'a reinforcedbearing structure fabricated fin accordance with the flange bendingmethod', 'it is 'necessary 'to utilize a generally elongated blank'provided with enlarged end perdons 'for forming the 'reinforced'bearing structures. The enlarged end 'portions of the 'blank 'contourdo not permit economical 'nesting 'on the original blank 'material sothat a'considerable vamount 'of rscrap results from the blankingoperation. VAccording to the present invention, a blank is placedbetween suitable die vmembers and a concentric'reinforcing ange for 'anembossment is 'formed by extruding the iiange simultaneously with theextrusion of the embossment.

` The drawing furnished herewith illustrates the best mode of carryingout the invention'as presently contemplated and set forth hereinafter.

In thev drawing:

FIGURE l is a fragmentary plan view of a blank for n v ehicle controlarm element showing the end portion vv'thereof which is 'to be providedwith' a ilange reinforced embossment or bearing structure inV accordance.with the Iinvention;

"FIG.` 2 is a partial longitudinal section showing the :formation of theange reinforced bearing structure on the blank of FIGURE 1 betweenextrusion die members;

" FIG. 3 'is a viewsirnilar to FIG.'2 showing .the ange 'reinforcedbearing structure between the fully .closed die members;

FIG. 4 is .a sectional view'as w'ewed from the right 'in FIG; 3 with thedie members open, showing the Iiiange reinforced bearing structure; and

FIG. 5 is a partial plan view of a vehicle control arm element showing aflange reinforced bearing structure made in accordance with thisinvention.

The method of the invention will be described in connection with thefabrication of a vehicle control arm element 1 as shown in FIG. 5. Theelement l is of generally channel-section having side anges 2 extendingover substantially the length thereof. A tubular embossment of bearingstructure 3 is provided in the web 4 adjacent to the end of the element.A reinforcing ange 5 is formed on the end of element 1 concentricallyabout the embossment 3 and integrally with the side ilanges 2.

The element 1 is formed from a generally elongated blank 6 having an endportion 7 of reduced width as e gaaanz Para@ Se* 12 liti "forth'e diemembers'and to prevent 'tearing ofthe blank material as the die'membjersmove together. The V'end ofthe blank is'rounded on a 'radiusY extendingfrom the center 8' .J l,

The blank '6 ris 'placed between 'complementary 'die members: 9 .and Y10 either o r both of'w'hich'are adaptervlt moverelatively 'with respectto' each other tov formv the control' arm elementi.` Asuitableknock-out,'not` shown, maybe provided inthe lower'die member 9for 4eje'cting the formed'elementfronmthe die'rnember.

The lowerY die"memberA9 iS'PrQvide/d with. e 'mesitadina'lly extendingrecess'qt Cavity lrhavins verfilly extending side .walls '12.' Acylindrical punch"13'havi1 rg a 'diameter 'somewhat' less vthanthe widthof recess '1'1 extendsupwardly from'ithe 'bottom 14 of the recess 'ad'''jacent one end thereof. "The upper annularjedge "ci punch 13 isgenerally rounded toprevent tearing offlthe metal'and 'a 'small' pilotyprojection 15 vextends ,upwardly from `thefpunch at the :center thereofto engage hole 8 'in the 'blank for centering the dies and 'blankrelatively. The serniQcylin'drical end wall'l' .of recess 11 is formedoncentrically about vpunch'li. .The side walls V12 ljoin the end 'wall16 on tangents extending .from a vertical ,transverseplane 'through `thecenter of fthe'punch toform position of "the" die` members the verticalwall of Tec s 'a continuous recess twall. The upper edge of' walls '12and'l is formed' with a'rounded'approach` 17 to prevent tearing of,metal- The complementary `upper die member 1t) has a cylindrical recessor cavity 1Sv which provides the'die'witltil downwardly extending-longitudinal section 19 having ver# tical side walls ,20 anti alrelatively thin semi-eireulaii `projection 2'1. fin the closed positionof the die 'members9 and 10, the .side walls 20 of section 19 are spaced`from the .side walls 12 of recess l1 to provide clearance therebetweenequal to the blank thickness, 'and the `lower 'surface ofsection 19 isvspaced from 'the bottom 14 of recess'll to provide similar clearance..Section 19 merges into the semi-cylindrical projection 2.1 and thediameter of 'thejlatter 'is somewhat greater than the distance betweenthe sidewalls V2;() offsection '19. Projection'21 isformedconcentrically with respect to the'end wall '16 of :recess 11 ofthe lower die member?, anlfn the' .closedposition of .the die members 9andjlllfis ,spacl 'inwardly therefrom an amount somewhat less than:

blank thickness. 'Because the distance between the louter ysurface of'projection 21A taken transversely throughllt `center'isgreater'than:thedistancebetween the ,side walls 120, the sidewalls narrow downtofJ'ointhe on a'genera'lly smooth curve.

Cylindrical recess 18 .isfprovided indie 10 toreceive the punch 1'13`ofthejlower diej'member 9. In the lsei projection "2:1

18""is' concentricl ,with and spaced 'from the punch to provide anannular clearance whose radial dimension is somewhat less than the blankthickness. Projection 21 is also radially spaced from the punch 13 andthe die 9 to provide an annular clearance on both sides of projection21. A pilot hole 22 is provided in the upper die member centrally ofrecess 18 to receive the pilot projection 15 on punch 13 and therebyguide the die members as they move relative to each other.

In carrying out the invention, the blank 7 of predetermined contour isdisposed over the lower die member 9 with the pilot projection 15engaging the hole 8 in the blank to properly align the blank withrespect to the die. The upper die 10 is then actuated downwardly and inthe first instance the lower surface of section 19 and projection 21engages the upper surface of the blank. As the upper die member 10continues downwardly, the pilot hole 22 receives the pilot projection 15to properly align the die members. A simple bendingoperation forms theblank into a channel-section element between the respective side walls12 and 19 and between the die section 19 and the bottom 14 of recess 11.7 Q

As the die section 19 and the die projection 21 advance downwardly theystart to extrude the metal behind them over the punch 13, as shown inFIG. Zand progressively push the metal ahead of the punch by a ilowingoperation to effect a gradual reduction in thickness of the. metal inthe circular embossment 3. FIGS. 3, 4 and 5 show the extrudedembossrnent 3.

Simultaneously with the extrusion of embossment 3, the concentric endflange 5V is formed on the control arm element v1. As the die projectionv21 moves downwardly` 'it causes the metal in end ange 5- to extrudevover the rounded edge 17 of recess end wall 16. The metal isprogressively pushed ahead of edge 17 by a flowing operation to effect agradual reduction to .the desired thickness of the end flange. While thethickness of end flange 5 is reduced from the original blank thickness,its thickness dimension may or may not equal the wall thickness ofvembossment 3.

' The projection 21 may have any predetermined thickness as long as ithas the strength and rigidity to withstand the forming pressures.Generally, the closer the end`flange 5 can be placed to the embossment 3the more eiciently it will operate to reinforce the embossment. Aprojection 21 having a radial dimension of oneeighth inch or less hasbeen used to successfully extrude blank material of @s inch thickness toeach side thereof simultaneously to form the reinforcing ange and theernbossment.

The success of the multiple extrusionis somewhat devpendent upon the owcharacteristics of the metal and the thickness of the stock.Theinvention is more adaptable to softer drawing steels having a lowcarbon content, preferably not in excess of .25% carbon. Successfulmultiple cxtrusions have been formed from .l-.15% carbon steel blankshaving a stock thickness of' inch.

Further, the edges of the small hole 8 in the blank 6 Aand the edge ofthe end perdon 1 'of the blank should be free of burrs or roughnesswhich might cause a tendency to start a tear.

As shown in FIG. 2 the extrusion of the metal forming the embossmentoccurs simultaneously with the extrusion of the metal forming the flangeportion concentric therewith, and as shown in FIG. both the circularemboss- :ment 3 and the flange portion 5 are substantially reduced`sible to employ substantially less metal at the end of "aseasia theblank. Embossment 3, being extruded is shown of great heighth thanflange portion 2 and also p rtion 5.

The term extruding as employed herein refers to the type of formingillustrated in FIGS. 2 and 3 wherein metal of the blank ows ahead of oneportion of the die as the dies close together with less space betweenthe opposed portions of the dies than the thickness of the blank.

The extruded flange permits a substantial reduction in blank size overthe previous bending methods because less material is required for theflange and the radial clearance between the flange and the bearingextrusion may besubstantially reduced. The strength characteristics ofthe thinner extruded ange remain substantially the same as that for theflange formed by bending as a result of the cold working on the metal.And further, because the extruded flange may be placed closer to thebearing extrusion, it is in a better position to provide reinforcementfor the bearing extrusion. In the case of vehicle control arm elementsthe invention permits utilization of a blank contour wherein the endportions are narrower than the remainder of the blank so that economicalnesting on sheet material is possible and scrap loss is greatly reducedduring the blanking operation.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claim particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

I claim: v

The forming of a ange reenforced cylindrical embossment on a dat metalblank in a single operation, comprising initially expanding a circularportion of the blank surrounding and immediately adjacent a preformedperforation therein by drawing the same over the gradually curved headof a male die member in forming the embossment, progressively extrudingthe drawn metal to form a tubular embossment on the blank of a thicknesssubstantially thinner than the blank, and extruding a reenforcing flangeclosely adjacent the tubular embossment and substantially reduced inthickness from the blank, said Vextruding of the ilange beingsimultaneous with the extrusion of theembossment to provide balancedforces on opposite sides of the intermediate die member and preventtearing of the metal as occurs where the extruding operations aresuccessive.

References Cited in the tile of this patent UNITED STATES PATENTS298,224 U Morgan May 6, 1884 866,024 Hansen Sept. 17, 1907 1,397,566Walter Nov. 22, 1921 1,580,930 Thackray -Apr. 13, 1926 1,581,680 yGueritey a. Apr. 20, 1926 1,672,694 Shrum Iune 5, 1928 l1,675,910 RikerJuly 3, 1928 2,112,653 MacLennan Mar. 29, i938 2,246,204 Graf June 17,1941 2,282,588 Y Lyon May l2, 1942. 2,738,575 v Swain Mar. 20, 1956

